Maths, inverse proportions

Question

Hello, could I receive an explanation  of how to solve questions that involve inverse proportions and ask for formulas.

 

The question is:

 

'y is inversely proportional to the square of x.

when x=5 and y=15

 

write the formula for y in terms of x.'

 

Thank you.

Answer 1

A formula of the variety y=x is proportional.

A formula of the variety y = 1/x is an inverse proportion.

 

If "y is inversely proportional to the square of x" then,

y = 1/x²

 

 

You can evaluate this with the given x=5

y=1/25